1. Field of the Invention
The present invention relates to an apparatus for fire detection in an electrical equipment rack comprising a suction pipe system which communicates with the electrical equipment rack to be monitored through at least one suction opening and through which a representative air sample is drawn from the electrical equipment rack to be monitored, an early fire detection module having at least one detector unit for detecting at least one fire parameter in the air sample extracted through the suction pipe system, and a controller for issuing a fire detection signal in response to the result detected with the at least one detector unit.
To be understood by the term “electrical equipment rack” as used here are all cabinets which accommodate electronic components or devices such as e.g. computer system racks, network racks, production control racks, electronic control racks or even telecommunication racks. Furthermore, “early fire detection” in the present description refers to the detection of a fire while still in its incipient phase whereby early fire detection of course also includes detecting fires which have already developed. It is, however, the objective of early fire detection to detect a developing fire in the so-called pyrolytic phase during which the material being heated, e.g. cable coilings, are already emitting smoke aerosols. The term “fire parameter” refers to physical variables which undergo measurable changes in the vicinity of an incipient fire such as e.g. the ambient temperature, the ratio of solids or liquids or gases in the ambient air (accumulation of smoke as particles or aerosols or vapors), or the ambient radiation.
Service and production enterprises are relying to a continually greater degree on the operability and the high availability of their computer installations. Therefore, large computing centers or electrical power plants place correspondingly high importance on fire prevention. Yet there are often only just a few or even singly-positioned network or control racks to ensure most of the working operations. Hence, various different departments of a company will make use of centrally-operated network racks or individual control racks. Regardless of their great importance, these equipment racks are frequently situated in areas unmonitored by fire alarm systems. These technical installations therefore often represent an underestimated risk because a fire not detected promptly can quickly lead to substantial disruptions in operations or production. In order to reduce possible damage from fire to the electronic “inner workings” of such equipment racks to its absolute minimum or even circumvent it altogether, very high requirements are placed on fire prevention and should include earliest detection, disconnecting the power supply, and fast as well as residueless extinguishing of the incipient fire.
2. Description of the Prior Art
An apparatus of the type cited above is known for example from DE 10 2004 048 233. The known prior art system comprises an apparatus for early fire detection which consists essentially of a fan unit and a detector for detecting a fire parameter using an air sample extracted with the fan unit. Specifically, it is provided to arrange the early fire detection apparatus above the housing of the equipment rack to be monitored, whereby the fan unit can draw the representative air sample out of the cooling air flow for the equipment rack.
Problematic to such a solution however is, on the one hand, the relatively large overall height of the fire detection system. On the other hand, for various reasons, it is often not possible or only possible with great effort to arrange the fire detection system on the housing cover for the equipment rack to be monitored. There is in fact often not enough installation space available above equipment rack housing covers to install such a system. This has the consequence that retrofitting an equipment rack with a fire detection system can only be done at great constructional effort and sometimes may not even be possible at all. Furthermore, a fire detection system installed on a housing cover often cannot ensure a sufficient dissipation of heat for the electronic or electrical components integrated in the equipment rack such that the operability of the components in the equipment rack is affected. The known fire detection system is also only suited to a limited extent to simultaneously monitoring a plurality of separate electrical equipment racks.